Answer:

Is it possible to draw the inner rectangle first, and then draw the rectangles that contain it?

Yes. This is an easy modification to the program.

Is is possible to reduce the scale each time by multiplying by 0.9?

Yes. This is an even easier modification to the program. You will get a different picture, though.

There are many other variations on this basic program. To really learn recursion, try some of them and invent your own. See the exercises.

Sweet Add Line

One sea-green line, diagonally across the scene

Here is a program that draws a line. It does this by calling addLine(), which adds one line with specified end points and Color to a Group .

Recall that class Line is a subclass of Shape, so it inherits all the methods of that class and its grandparent class Node.

import javafx.application.*;  
import javafx.stage.*;        
import javafx.scene.*;  
import javafx.scene.shape.*; 
import javafx.scene.paint.*;  
 
public class DrawLine extends Application
{ 
  
  void addLine( Group root, Color color, double startX, double startY, double endX, double endY )
  { 
    Line line = new Line( startX, startY, endX, endY );
    line.setStrokeWidth( 3.0 );
    line.setStroke( color );
    root.getChildren().add( line );  
  }
  
  public void start(Stage stage) 
  { 
    double sceneWidth=400, sceneHeight= 300;  
    double startX = 20.0, startY = 250.0, // left end point
           endX = 380.0, endY = 50.0;     // right end point
    Group  root = new Group( );   
    addLine( root, Color.DARKSEAGREEN, startX, startY, endX, endY );
    
    Scene scene = new Scene(root, sceneWidth, sceneHeight, Color.BLANCHEDALMOND ); 
    stage.setTitle("One Line"); 
    stage.setScene(scene); 
    stage.show(); 
  }      

}

Answer:

Sweet Add Line

QUESTION 10: